Loud speaker



Nov. 3, 1925. v I 1,559,777

E. J. REICH El AL LOUD SPEAKER Filed Nov. 26. 1923 INVE TORS 716;, ATTORNEY Patented, Nov. 3, 1925.

UNITED STATES 1,559,777. PATENT OFFICE.

EDWIN J. REICH, F BROOKLYN, AND GEORGE J'. ELTZ, JR., OF NEWYORK, N. Y., ASSIGNORS T0 MANHATTAN ELECTRICAL SUPPLY COMPANY, INC., OF NEWYORK, N. Y., A CORPORATION OF MASSACHUSETTS.

I LOUD SPEAKER.

Application filed November 26, 1923. Serial No. 676,918.

To all iohom it may concern:

Be it known that we, EDWIN J. Baron,-

residing at Brooklyn, New York, in the county of Kings and State of New York,v

United States of America, and GEORGE J. ,ELTZ, J r., residing at 96 Wadsworth Terrace, New York city, New York, having invented certain new and useful Improvements in Loud Speakers, do hereby declare that the following is a full, clear, and exact description of the same.

This invention relates tonew and useful improvements intelephonic receiving elements, and more particularly to improvements in telephone loud speakers.-

It is the object of this invention to provide a telephone loudspeaker which is simple in construction and operation, and which -*may be readily adjusted to vary the tone output.

With this object in view, the magnet structure is mounted on a relatively heavy base the inertia of which will tend to maintainthe magnets in their adjusted position. According to another feature of the invention, a leaf spring formed into substantially a circleis placed under tension in res onse to all relative displacements of said diaphragm and magnet structure and this serves to aid in maintaining the spacing between the two. I

These and other features of the invention will more clearly appear from the following detailed description of a preferred em-- bodiment thereof and the appended claims.

The drawings illustrate a telephone loud speaker exemplifying the various features of t e present invention. Fig. 1 is a side elevation with parts broken away; Fig. 2 is a top plan view; Fig. 3 is a cross section of the receiving element proper contained in the loudspeaker; Fig. 4.- 1s a bottom plan view of the receiving element; and Fig. 5 is aperspective view of a spring by means of which. the receiving element is held in its adjusted position.

Referring now to the drawings, 1 is a cup proyided with a solid and relatively heav base 2 and arranged to enclose the tele onic receivin element. The open end of t e cup is closer? by a top 3 held 1n position by means of bolts such as 4.- projecting through the base 2 and engaging with their screw-threaded ends internally screw threaded apertures 5 provided in the top 3; The top 3 is centrally perforated at 6, said perforation being surrounded by a collar 7 forming a unitary structure with the top 3. An amplifying-horn .(not shown) may be fitted over this collar 7. p I The lower face of the to 3 is recessed 1n a manner to form a shoul er 8 and an internally screw threaded rim' 9, The internally screw threaded rim;.9 cooperates with the externally screw threaded end of a cylindrical casing 10 which contains the magnet structure of the receiver. A thin steel diaphragm 11 is firmly clamped against the shoulder 8v by the cylindrical casing 10. The central (part of the cylindrical casing 10 is provide with a horizontal strengthening rib 12, the casing 10 being further strengthened due to the provision of outwardly projecting vertical ribs 30. The lower part of casing 10 is internally screw threaded to cooperate with an external screw-thread provided on a disc 13. Themagnet coils 14 and the horse-shoe 15 by means of which the magnetic circuit is completed, are mounted on the disc 13 by means of bolts 16 traversing perforations'in. said disc and having screw threaded ends cooperating with nuts 17. The horse-shoes 15 and the magnet coils 14 are spaced from the upper face of the disc 13-by means of a suitably shaped washer 18. The disc 13 is perforated at two other points where two inding osts 19 and 20 project through it, said bin ing posts being properly insulated from each other and from the disc 13 by means of insulation 21. The terminal wires of the coils 14 are connected to the ends of these binding posts 19 and 20 projecting through the upper face of the disc 13 ('not shown).

Small erforations or indentations 22 provided 1n a centrally located raised portion of disc 13 are adapted to reoeive In S 23-projecting from a lever 24 which may e held against the disc 13 by means of a screw 25. The lever 24 may be adjusted into any position with the lugs 23 engaging two opposite holes 22 and then maintained in such position by tightenin the screw 25. When the lever 24 is thus rmly held in position then, by means of it, the disc 13may be rotated in a clockwise or a counterclockwise direction. When the disc is thus rotated'in as clearly shown in Fig. 5 is bent into a shape that has vthree raised and three lowered portions, is provided between the cylindrical casing 10 and the disc 13. The three lowered points engage the shoulder formed by the rib 12 and the three raised points engage the disc 13 around its periphery. The spring 27 is split at 28 to permit a relativel wide play. After the disc 13 is screwe "into place and the spring 27- placed under tension, such spring will remain under tension while the disc is rotated back and forth within desired mar ins and thus the magnet structure will e held through the agency of this spring in whichever position it is desired.

In addition to' the spring 27, the magnet structure is maintained in its adjusted osition due to the fact that the disc 13 1s of relatively heavy material and its inertia will have therefore a tendency to prevent vertical displacements of the magnet structure. The provision of spring 27 and the weight of disc 13 avoids the necessity of providing specialmeans for locking the magnet structure in its adjusted position. Not only is the pro vision of such special holding and locking means done away with, but also the screw thread by means of which the disc 13 is held in the cylindrical casing 10 may be ve coarse, whereby the cost of manufacturing and assembling is materially reduced and 'a relatively slight movement of the lever 24: will result in a relatively large vertical displacement of the-magnet structure 14 with respect to the diaphragm 11, permitting thus readily to modulate the ton output.

What we claim is:

1. In a telephone loud speaker, a casing,

a diaphragm, means for clamping the edge I of said diaphragm against the upper end of said casing, a disc screw-threaded around its periphery and cooperating with the inm said casing, a r

ternally screw-threaded lower end --of said casing, a magnet structure carried by said ,disc, an internal projection on said casing near its lower end, and a spring placed under tension between said projection and said disc. 1

2. In a telephone loud speaker, a cup, a top therefor, a casing fastened to said top, a diaphragm held between said top and the upper end of said casing, a disc screwthreaded around its periphery and cooperating with the internally screw -threaded lowerend of said casing, a magnet structure mounted on said disc, and a substantially circular spring exerting uniform pressure screwed into place, a lever fastened to said .disc, and a slot in said cup through which the free end of said lever projects.

4. In a loud speaker, a cup having a relatively heavy base and a top, an aperture in said top, a collar projecting from said top and surrounding said aperture, 9. metallic diaphragm seated in-an inner recessed portion of saidtop, a casing having an ex ternally screw threaded upper end adapted to engage aninternal screw thread in said recessed portion to clamp said diaphragm in place, an inwardly projecting horizontal rib e atively heavy disc provided with a relatively coarse external screw thread, a magnet structure mounted on said disc, a relatively coarse inner screw thread on the lower portion of said'casing cooperating with the external screw thread. on said disc, a split-leaf spring having a plurality of raised and lowered portions engaging one face of said rib and saiddisc around its periphery when the disc is. screwed into place, a lever fastened to said disc, and a slot in'said cup through which the free end of said lever projects.

In witness whereof, we hereunto subscribe our names this 21st day of November, 1923.

GEORGE J. ELTZ, JR. EDWIN J. REICH. 

